Hydrocarbon substituted polycyanotetrahydrofuran lubricating oil detergents



United States Patent 3,442,809 HYDROCARBON SUBSTITUTED POLYCYANO-TETRAHYDROFURAN LUBRICATING OIL DETERGENTS Garth M. Stanton, Pinole,Calif., assignor to Chevron Research Company, San Francisco, Calif., acorporation of Delaware No Drawing. Filed July 21, 1966, Ser. No.566,743

Int. Cl. C10m 1/20 US. Cl. 252-515 4 Claims ABSTRACT OF THE DISCLOSUREAliphatic hydrocarbon substituted polycyanotetrahydrofurans are providedas lubricating oil detergents.

This invention concerns novel cyano substituted tetrahydrofuranderivatives which find use as detergents in lubricating oils.

A development of major importance in the lubricating oil field has beenthe introduction of ashless detergents, that is, metal free compoundswhich are capable of reducing varnish and. sludge deposits in internalcombustion engines. An important advantage of these ashless detergentsis the avoidance of the ash formed by the metal salt detergents ondecomposition. Thus, valve and combustion chamber deposition withaccompanying octane requirement increase can be minimized through theiruse.

It has now been found that lubricating oil detergents are provided bycompositions of the formula:

wherein R to R are hydrogen or aliphatic hydrocarbon having a total offrom 30 to about 400 carbon atoms, more usually 30 to 300 carbon atoms,and may be aliphatically saturated or unsaturated.

For the most part, the compositions will have the following formula:

wherein at least one of R R and R is aliphatic hydrocarbon while theother two may be hydrogen or aliphatic hydrocarbon, the total number ofcarbon atoms of R R and R' being in the range of 30 to 300, more usuallyin the range of 50 to 200. Usually, two of R R and R will be hydrogenand/ or lower alkyl.

The compositions of this invention may be readily prepared by contactingan aliphatic hydrocarbon olefin with tetracyanoethylene oxide which hasthe following formula:

The olefins which find use may be naturally occurring or syntheticstraight chain, but preferably branched chain. Usually, the desiredolefins can be obtained by polymerizing lower molecular weight olefinsto a high molecular Weight olefinic product.

Illustrative olefins include ethylene, propylene, butene-l, isobutylene,4-methylpentene-1, either individually or in combination. The preferredolefins are propylene and isobutylene, i.e., olefins of from 3 to 4carbon atoms.

The reaction is carried out by contacting the tetracyanoethylene oxideand olefin in an inert medium at elevated temperatures. The temperatureis generally in the range of about 50 C., to 150 C. Depending on thetemperature, the reaction time may vary from 1 hour to 24 hours. Theratio of the reactants is generally approximately stoichiometric. Aninert solvent is usually used, either an aromatic hydrocarbon or ahalohydrocarbon, e.g., toluene, 1-bromo-2-chloroethylene, etc.

The reaction product is readily obtained by removing the volatilematerials in vacuo, dissolving the residue in inert aliphatichydrocarbon, e.g., hexanes, and then extracting the hydrocarbon solutionwith an alkanol, e.g., ethanol. After drying the hydrocarbon layer, thevolatile materials are removed and the product obtained.

The lubricating fluids (hereinafter referred to as oils) which arecombined with the detergent compounds can be derived from natural orsynthetic sources. Oils generally have viscosities of from about 35 to50,000 Saybolt Universal Seconds (SUS) at 100 F. Among naturalhydrocarbonaceous oils are paratfin base, naphthenic base, asphalticbase and mixed base oils. Illustrative of the synthetic oils are:hydrocarbon oils, such as polymers of various olefins; and alkylatedaromatic hydrocarbons; and nonhydrocarbon oils, such as polyalkyleneoxides, aromatic ethers, carboxylate esters, phosphate esters, andsilicon esters. The preferred media are the hydrocarbonaceous media,both natural and synthetic.

The above oils may be used individually or together, whenever miscibleor made so by the use of mutual solvents.

When being used in an internal combustion engine, the detergent Willgenerally be compounded with the lubricating oil in amounts of at leastabout one Weight percent and usually not more than 20 Weight percent,more usually in the range of about 1.5 to 15 Weight percent. Thedetergents, however, can be prepared as concentrates due to theirexcellent compatibility with oils. As concentrates, the compounds ofthis invention will generally range from about 20 to weight percent ofthe total composition.

Usually included in the oils are other additives, such as extremepressure agents, rust inhibitors, antioxidants, oiliness agents, foaminhibitors, viscosity index improvers, pour point depressants andoccasionally other detergents. Usually, these will be present in therange from about 0.01 to 10 weight percent, more usually from about 0.5to 5 Weight percent of the composition; generally, each of the additiveswill be present in the range from about 0.01 to 5 weight percent of thecomposition.

A preferred aspect in using the detergent containing lubricating oilcompositions of this invention is to include in the oil from about 1 to50 mM./kg. of an 0,0-dihydrocarbyl phosphorodithioate, wherein thehydrocarbyl groups are from about 4 to 30 carbon atoms. The remainingvalence may be satisfied by zinc, a polyalkyleneoxy or a thirdhydrocarbyl group. (Hydrocarbyl is an organic radical composed solely ofcarbon and hydrogen.)

The following example is offered by Way of illustration and not by Wayof limitation.

Example I (665) Into a reaction flask was introduced 35 g. ofpolyisobutylene (0.03 mole) and 5 g. of tetracyanoethylene oxide (0.035mole) and toluene added to form a 50 weight percent solution. The mixwas refiuxed in an inert atmosphere for 10 hours.

At the end of this time, the volatile material was stripped olf invacuo, maintaining the temperature below 50 C. The residue was dissolvedin about an equal weight of hexanes and ethanol added. Water was added,until separation of two layers became obvious. The water layer was thendiscarded, and the procedure repeated three times until the water layerwas virtually colorless. The organic layer was then stripped of volatilematerials in vacuo leaving the product. Analysis: Percent N, 2.96(indicates some unreacted polyisobutylene present). An infrared spectrumwas consistent with the tetracyanotetrahydrofuran product.

In order to demonstrate the effectiveness of the compositions of thisinvention, the exemplary composition of Example I was tested in amodified FL-Z test procedure, as described in the June 21, 1948 reportof the Coordinating Research Council. This test simulates automobileengine performance. A standard procedure requires the maintenance of ajacket temperature of 95 F. and a crankcase oil temperature of 155 F. at2,500 rpm. and 45 brake horsepower for 40 hours (closely simulating therelatively cold engine conditions which are normally experienced in citydriving). At the end of each test, the engine is dismantled and theamount of total sludge and varnish (rating of to 100, no sludge andvarnish being 100) and clogging of the rings and oil screen (rating of 0to 100, no clogging being 0) is determined. The above test was modifiedby increasing the time for the test and periodically raising the oilsump temperature from 165 F. to 205 F. and the water jacket temperaturefrom 95 F. to 170 F.

Using a Mid-Continent SAE 30 base stock, the exemplary detergent ofExample I was employed at 1.56 weight percent concentration. Alsoincluded in the oil was mM./kg. of zinc 0,0-di(alkyl dithiophosphate)(alkyl of from 4 to 6 carbon atoms) and 2 mM./ kg. of zinc 0,0-di-(alkylphenyl) dithiophosphate (alkyl is polypropylene of from 12 to 15carbon atoms). At the end of 60 hours, total sludge and varnish wererated at 50.7%, percent oil ring clogging at 83 and percent oil screenclogging at 20. With base oil, the engine is usually incapable of anyfurther operation after about 12 hours.

It is evident from the above results that the compositions of thisinvention provide excellent detergency and lubrication in internalcombustion engines. The presence of the cyano group also aids inproviding some corrosion inhibition, particularly with lead copperbearings.

As will be evident to those skilled in the art, various modifications onthis invention can be made or followed, in the light of the foregoingdisclosure and discussion, without departing from the spirit or scope ofthe disclosure or from the scope of the following claims.

I claim:

1. A composition useful as a lubricating oil detergent, said compositionhaving no more than about 400 carbon atoms and having the formula:

wherein at least one of R to R is aliphatic hydrocarbon having at least30 carbon atoms and the remaining of R to R being selected from thegroup consisting of hydrogen and aliphatic hydrocarbon.

2. A composition according to claim 1, wherein the total number ofcarbon atoms of R to R is in the range of to 200.

3. A composition according to claim 1, wherein at least one of R to R isderived from polyisobutenyl.

4. A lubricating oil composition having in an amount sufficient toprovide detergency, a composition according to claim 1.

References Cited UNITED STATES PATENTS 2,766,247 10/1956 Middleton25251.5 XR 3,184,457 5/1965 Brannock et a1. 25251.5 XR 3,235,565 2/1966Linn 260346.1 3,317,567 5/1967 Linn 260346.1

PATRICK P. GARVIN, Primary Examiner.

U.S. Cl. X.R.

